Pulp bleaching apparatus and method
CA 2128241 C · Owner: Pikulin, Michael · Inventors: White, David C.; Gandek, Thomas P.; Pikulin, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus and method for bleaching, high consistency lignocellulosic pulp using ozone supplied in an ozone containing gas. The bleaching reactor apparatus according to the invention is a generally cylindrical vessel (42A 42B) with a, rotatable shaft (48B) having radially extending paddles (52B) or other conveying elements arranged in a configuration to minimize axial dispersion of the pulp and maximize radial dispersion of the pulp to provide a radially dispersed plug flow of pulp through the reactor in the presence of the ozone to provide substantially uniformly bleached pulp.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 24, 1992 and granted September 5, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.